Retaining walls are used in various landscaping projects and are available in a wide variety of styles. Numerous methods and materials exist for the construction of retaining walls. Such methods include the use of natural stone, poured concrete, precast panels, masonry, and landscape timbers or railroad ties.
In recent years, segmental concrete retaining wall units, which are dry stacked (i.e., built without the use of mortar), have become widely accepted in the construction of retaining walls. Such retaining wall units have gained popularity because they are mass produced and, consequently, relatively inexpensive. They are structurally sound, easy and relatively inexpensive to install, and couple the durability of concrete with the attractiveness of various architectural finishes.
The shape of the block is also an important feature during installation of a retaining wall. Many commercially available blocks are symmetrical about a plane bisecting the front and back surfaces. Typically such blocks have planes rather than axes of symmetry, as there are differences between the top and bottom surfaces of such blocks. Clearly, blocks that are substantially square or rectangular (i.e., each surface being joined to another at an orthogonal angle) exhibit a great deal of symmetry. There are advantages to having non-parallel surfaces on these blocks when constructing a retaining wall. The angles formed by these side surfaces permits construction of curvilinear walls, and moreover, permit the amount of curvature to vary according to the terrain and desired appearance of the retaining wall.
In the manufacture of retaining wall blocks and other kinds of blocks made from concrete, it is common to use a mold that forms a block module which is then split to form two or more blocks. When a block module is split, the split surface has an irregular appearance, which is desirable if the desired look is one of natural stone. In forming block modules of such blocks, it is often standard practice to split a block module on a plane coincident with the front faces of two blocks, thus giving the front faces of two opposing blocks an irregular (i.e., roughened) appearance.
Additionally during the manufacture of the block, separate core support bridges (similar to core bars) help support interior void forming elements such as open cores, pin holes and the like, which span the cavity of the mold during production and allow the concrete to flow around and under these support bridges. Regular over the top of mold core bars may leave undesired troughs or blemishes on the surface of the block where the core bars pass over the face or surface area of the block. Numerous core bars in a mold may result in inconsistent material distribution inside the mold cavity and can create problems in achieving good compression results in the concrete material.
Another important feature of retaining wall blocks and blocks used in free standing walls is the appearance of the block. Creating a uniform and consistent look is very appealing for walls. Additionally, the look of weathered natural stone is very appealing for walls. There are several methods in the art to produce concrete wall blocks having an appearance that to varying degrees mimics the look of natural stone. One well known method is to split the block during the manufacturing process so that the front face of the block has a fractured concrete surface that looks like a natural split rock. This is done by forming a single large unit in the mold cavity and providing one or more splitting grooves in the single unit to function as one or more splitting planes. The single unit is then split apart to form two or more blocks. Another method is wherein blocks are individually formed in a mold and the surfaces are textured by removal of the mold. Another known method of creating a block having an irregular or textured surface is to form the block in a mold box that has been provided with a sidewall liner shaped to impart the irregular or textured surface on the block during the block molding process.
Wall block systems are also generally provided with some means to connect blocks in adjacent courses of the wall, such as a pinning system. The pinning system generally connects adjacent courses in a wall together thereby strengthening the wall and increasing stability of the structure. The pinning system can also align the courses of adjacent blocks to produce a set-back or a near vertical wall.
It would be desirable to provide a wall block having full depth cores which lighten the block weight for use in constructing a wall, retaining wall, fence or the like.
It would be desirable to provide a wall block having a chamfer on the sides and top of the front face of the block, to reduce the probability of sustaining damage to the block edges during manufacture, plant-handling, transportation and site installation handling. It would further be desirable that the sides and top of the front face of the wall block have an angled chamfer which creates block edges that are greater than 90° from a vertical plane formed from the sides and front of the block. The greater than 90° edges are harder to chip off or wear away during manufacture, plant-handling, transportation and site installation handling, and thereby minimize any damage to block edges.
It would be desirable to provide a system of blocks for constructing a wall that combines the ease of installation of modern segmental wall blocks with the attractive appearance of an aesthetic design. It would also be desirable to provide a retaining wall system that allows an aesthetically pleasing uniform appearance.
It would further be highly desirable to have a wall block system which can be used to build a retaining wall using a pin connection between courses, depending on the requirements of the project. Such a unit would also be desirable from a production and distribution view point, because the same block design could be used in multiple wall applications, thus reducing the need to produce specialty units.
It would be further desirable to provide a wall block system for the construction of a wall, retaining wall and the like having a pin connection system whereby the courses of the wall being constructed are aligned by a core of the block when the inserted pin of the pinning system engages a wall of the core of the block. This method of supporting the pin core is also a benefit in that it eliminates the need for additional core bars or supporting bridges.
It would be further desirable to provide a wall block system for the construction of a wall, retaining wall and the like having a pin connection system that may allow setback of the structure being constructed. It would be further desirable to provide a wall block system for the construction of a wall, retaining wall and the like having a pin connection system that may allow near vertical construction of the structure.
It would further be desirable to provide a mold box utilizing a recessed forming member to produce a core rather than a standard core bar as known in the art. It would further be desirable to provide a mold box utilizing a recessed forming member that can produce a core and a pin hole. It would further be desirable to provide a mold box utilizing a recessed forming member that can produce a core, pin hole and receiving channel.